A light emitting module for backlighting a liquid crystal display or a light emitting module used for a flat lighting apparatus generally includes light emitting elements mounted on a substrate and a lens diffusing light emitted from the light emitting elements at a wide angle. A smaller number of light emitting elements may uniformly irradiate a wide area by uniformly dispersing light emitted from the light emitting elements using the lens.
FIG. 1 is a schematic cross-sectional view for describing a light emitting module according to the related art.
Referring to FIG. 1, the light emitting module includes a substrate 10, a light emitting element 20, and a lens 30. The substrate 10 is a printed circuit board on which a conductive pattern (not illustrated) is formed.
The light emitting element 20 includes a main body 25 having recesses, light emitting diode chips 21 mounted within the recesses, and a molding part 23 covering the light emitting diode chips 21 mounted within the recesses. The molding part 23 includes a phosphor which wavelength-converts light emitted from the light emitting diode chip 21. The light emitting element 20 is electrically connected to the conductive pattern of the substrate 10.
Meanwhile, the lens 30 has leg parts 31, in which the leg parts 31 are attached to the substrate 10 and thus are disposed on the light emitting element 20. The lens 30 has a light incident surface 33 on which the light emitted from the light emitting element 20 is incident and a light emitting surface 35 through which the incident light is emitted. The light incident surface 33 is provided at a lower portion of the lens 30 in a concave form.
The light emitting module according to the related art diffuses the light emitted from the light emitting element 20 through the lens 30 to be able to implement uniform light over a wide area. However, since the light emitting module has the light emitting element 20 mounted on the substrate 10 and the lens 30 mounted on the substrate 10 through the leg parts 31, there is a limitation in slimming the light emitting module. Further, since the light emitting module adopts the main body 25 having the recesses, a size of the light emitting element 20 is relatively large, and therefore a size of the lens 30 is relatively large.
Further, to implement a uniform surface light source, the light emitting diode chip 21 within the light emitting element 20, the light emitting element 20, and the lens 30 need to be precisely aligned, but the light emitting module according to the related art needs to precisely position all of the light emitting diode chip 21, the light emitting element 20, and the lens 30, and therefore there is a limitation in reducing an alignment tolerance.